Problem: $ { \left[\begin{array}{rrr}{0} & {1} & {3} \\ {1} & {2} & {-1}\end{array}\right]+\left[\begin{array}{rrr}{4} & {-2} & {1} \\ {0} & {-1} & {0}\end{array}\right] = {?} } $
Answer: To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rrr}{0}+{4} & {1}+{-2} & {3}+{1} \\ {1}+{0} & {2}+{-1} & {-1}+{0}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{4} & {-1} & {4} \\ {1} & {1} & {-1}\end{array}\right]}$